These office baby showers for dad are usually meant as a surprise, as he's more embarrassed than anything by all the attention. A nice touch would be to invite his wife, who would be more than happy to be there.
Actually, not much needs to be changed even if the guest of honor is male! The same rules apply for a office baby shower for dad or mommy-to-be.
You need to get permission to hold the baby shower on the office premises, whether it's in a spare conference room or the cafeteria. In any case, if the office baby shower for dad is during office hours, even during lunch hour, it's best to plan a celebration that will not be as noisy or possibly as disruptive as it would be if held in a home.
When that permission is secure, ask about schedules. The best time would be around lunch, or after office hours when everyone is done working. Confirm the daddy-to-be's free day and inform everyone else about it. If the office baby shower for dad can't be held on company premises, reserve a place at the local restaurant about a month before the scheduled shower, and confirm your reservation a week before the actual date.
While making the shower for dad a surprise, you could involve the mommy-to-be in part of the shower planning and as a source for more information, like where the baby registry is, and things the daddy-to-be doesn't like.
Because the baby shower is more of a female-oriented celebration, choose a theme and decorations that won't have your male co-worker running out of the party. Keep everything as unisex as possible, even if the new baby is going to be a girl.
Themes that men and women are comfortable with are colors, holidays, books, sports, or anything to do with the outdoors like camping or the beach. Don't use anything too girly to decorate, although pink wrapped chocolate cigars will definitely be welcomed.
Keep the food simple too, but a little heavier than normal. Burgers
and fries, a one-pot chili with bread, or a meat and cheese platter
are all great choices. Dessert is still needed, of course, but instead
of an elaborate cake, cupcakes or a pile of cookies would be just
perfect.